1. Field of the Invention
This invention relates generally to the art of changing work rolls in a rolling mill, and is concerned in particular with an improved tool for changing so-called "overhung" work rolls in rod and bar mills.
2. Description of the Prior Art
As part of the ongoing effort to increase the production efficiency of rolling mills, more attention is being focused on minimizing the down time occasioned by the need to change work rolls. To this end, mechanical manipulators and robots are being developed to assist operating personnel in performing this task as rapidly as possible. However, efforts to effectively utilize manipulators and robots have been frustrated by the handling complexities associated with conventional roll changing tools.
More particularly, overhung work rolls are conventionally fixed to the tapered ends of roll support shafts by means of tapered sleeves interposed in wedged engagement therebetween. A variety of hydraulically actuated tools have been developed to provide the considerable axial force required to seat and unseat the tapered sleeves. In some cases, two tools are required, one to seat the sleeves during roll mounting, and the other to unseat the sleeves during roll removal. In other cases, one tool accomplishes both functions by having its opposite ends adapted respectively to seat and unseat the sleeves.
In cases where two tools are required, the manipulators or robots must either be provided with two sets of arms, thereby increasing costs and operating complexities, or the tools must be manually interchanged, with considerable attendant lost time. In cases where one tool has its opposite ends adapted to handle both sleeve insertion and sleeve removal, the tool must be turned end to end during each roll changing operation. This again unduly increases operating complexities.
A primary objective of the present invention is to provide a novel and improved hydraulic tool which can accomplish both the sleeve insertion and sleeve removal functions without the need to turn the tool end to end.
A companion objective of the present invention is to provide a hydraulic tool which is simple to operate and consequently easily adaptable for use with mechanical manipulators, robots, or the like.